Etymology

The name Nott may be derived from Nótt, the personification of night in Norse mythology. It is also similar in pronounciation to the words "naught" and "knot".

Behind the scenes

It is possible that the family is not all "truly pure-blood" and if Cantankerus Nott is the author of the Pure-Blood Directory, then he probably just listed the Nott family so they would get praised by other supremacists. However, on an old version of her website, Joanne K. Rowling described Theodore Nott as being as pure-blood as Draco. This doesn't exclude the possibility that some Notts were half-bloods, as Pottermore confirmed that some half-blood Malfoys exist.